Containers having associated applicator caps for dispensing materials held within the container are well known. Typically they comprise a cap/applicator assembly which is adapted to be threadibly received on a bottle. Usually, the applicator has a head which engages within a housing formed by the cap. However the applicator may be integrally formed with a cap, so that its stem projects from the cap. The applicator usually has a stem which projects from the head. At the free end of the stem are filaments or other suitable means typically in the form of an applicator element, for applying the contents of the container to a desired surface. Conventionally the cap/applicator assembly is fitted to a bottle or other container by screw threading the cap onto the neck of the bottle. In this arrangement the cap/applicator assembly is inserted into the bottle so that the stem projects downwardly into the container when the applicator cap is in place on the container. It is usual that the stem and associated filaments extend to the bottom of the container. In this arrangement it is usual that at least a portion of the stem projects into the contents of the container. The cap thus serves a dual function, closing the container and secondly holding the applicator. The cap is typically held by hand when removed from the container. Product on the applicator can be applied by manoeuvring the cap to contact the applicator (in particular the applicator element) to the desired surface. Product is thus applied to the surface.
There are problems associated with various containers having applicator caps due to their particular construction. The nature of the product contents of the container may also cause additional or exacerbate already existing problems with the applicator caps. For instance the particular problem associated with curable compositions such as CA's is that the container must provide an environment as free as possible from environmental contamination. The cap should also seal the container closed. Contamination of the product may cause premature curing so that the product becomes unusable. Fouling of the cap and/or the applicator is also problematic with many products which dry or harden to a solid. This is a re-occurring problem. For instance, curable products, tend to adhere to the underside of the cap making it difficult to replace the cap so as to properly seal the container, thus exacerbating the problem. It will be appreciated that this problem is not exclusive to curable products and occurs with other products, for example correcting fluids and cosmetic compositions. Furthermore, the applicator and in particular its stem and free end, should remain as free as possible from dried or solidified (and in particular cured) product to allow for ease of application of product during subsequent use.
Curable product which manages to find its way onto the underside of the cap tends to cure at a later stage. This can adhere the cap to the container making manual removal of the cap difficult or even impossible so that the entire container may be discarded, even though it still contains otherwise useable product. The product may also find its way into screw threads on the cap where it dries/hardens on the screw threads making removal and subsequent re-threading of the cap on the container difficult.
Furthermore as the applicator cap and container contact the CA, the materials used for manufacturing the cap, the applicator and the stem have to be CA compatible materials, i.e. they must not react with the CA's. Typical compatible materials used include: polypropylene (PP), high density polyethylene (HDPE) or low density polyethylene (LDPE). At least some grades of these materials are compatible with CA's. The selection of the material (usually a plastics material) is thus limited. It has been found that in some instances adding colour to a natural plastic material contaminates CA products contacting the coloured plastic and may initiate cure of the product thereby compromising storage stability. There has thus been a tendency to avoid colouring all components which contact the CA. Also some CA compatible plastics do not take well to colouring. In order to reduce the possibility of contamination of the CA the plastics material is usually colourless. It would be useful if at least part of the applicator cap could be constructed of a plastic which takes colour well. The choice of material is greater if CA compatibility does not have to be considered.
In filling processes for containers closed by applicator caps such as those described above, in order to obtain a reliable seal between the cap and the container a quite substantial torque may be used (particularly where the product is air sensitive) to tighten the screw-threaded cap onto the container. The torque used is sufficiently high to cause difficulties to some users relying on manual pressure applied to the cap to unscrew it from the container for use. This is undesirable as the end user may forsake using the product due to difficulty in removing the cap.
This problem is common for filling processes where an insert is placed in the container. It is known in containers having an applicator cap to provide an insert in the neck of the container. The insert has an external profile which matches the internal profile of the neck of the container. A central aperture is located in the insert which allows the applicator access to the container. It is usual also to provide a wiper surface in the form of a circular lip or rim on the inside of the insert extending about the central aperture which wipes along the applicator stem as the applicator is removed from the container, wiping excess product from the stem before it is removed from the container. The insert may also act as an anti-spill device which helps to retain product in the (uncapped) container even if the container is tipped over.
Filling processes include one known process where the insert is engaged within the housing of the applicator cap and the cap/insert assembly is then applied to the (filled) container. In this arrangement the action of screw-threading the cap onto the container is also used to engage the insert in the neck of the container. Retentive engagement of the insert in the neck of the container is achieved by tightening the cap securely on the container. This filling process suffers the problem of subsequent difficulty of removal of the cap due to the relatively high torque used to tighten the cap which is necessitated by the desire to correctly position the insert.
In cases where the user manages to disengage a cap from the container despite the presence of cured product between the cap and the container, which adheres the applicator and/or cap to the container, the applicator may be sufficiently well adhered to the container so as to become disengaged from the cap and remain seated on the neck of the container. This situation is clearly undesirable as in addition to destruction of the applicator/cap assembly the product within the container remains inaccessible to the user.
In the manufacture of conventional brush applicator caps, the process typically involves two steps, the first step involving the individual manufacture of the applicator and the cap, and the second the attachment of the applicator to the cap. The manufacture of the brush applicator involves the additional steps of extruding filaments, and then cutting, stapling and assembling them into the stem of the applicator.
Typically the second step is securing the applicator to the cap. The applicator for conventional brush applicators are formed by push fitting or snap-fitting the applicator, in the housing of the cap. The applicator is thus secured in the cap The filaments located on the end of the applicator stem are usually fragile and are easily damaged for example in production processes or in the fitting process described above. An applicator with damaged filaments is usually discarded. Assembly of the applicator cap is carried out before the applicator cap is applied to a filled container.
Finally the applicator cap is presented to a filled container and threadibly engaged on the neck of the container to close the container. As stated above if an insert is to be placed in the neck of the container the insert may be engaged in the housing of the cap as described above, or alternatively inserted into the neck of the container before the applicator cap is applied.
It is desirable for aesthetic and other reasons, such as ease of manual gripping to align a profile for example grips of an applicator cap to the profile of a container to which the applicator cap is applied. Normal filling processes allow fitting of an applicator cap at relatively disperse positions on the container, as the final position of the applicator cap is determined by applying the cap until a certain torsional force is achieved, rather than determined by its relative position to the container on which it is placed.
Furthermore, many products held within containers and particularly those applied with applicator caps are harmful if misused, for example contacted with certain parts of the body such as the eyes, or ingested etc. The dangers of such products are most real for those who do not appreciate the harm that they may cause. Accordingly it is desirable to provide a safety applicator cap, i.e. a cap which is difficult to open without using a predetermined procedure to open the cap. Such safety devices are often referred to as “child-proof” or “child-safety” caps, as it is the very young who often are most at risk if they inadvertently gain access to the contents of the container. Such safety caps are used on many types of containers, for example those which hold cleaning fluids or correcting fluids, pharmaceutical containers etc.
In view of the foregoing there is a need to provide an alternative procedure for filling and closing a container with an applicator cap, particularly during a process to prepare a filled container of dispensable material. There is also a need to make the applicator itself simple and more robust, in an effort to improve throughput during the manufacturing process.
There is also a need for an applicator and applicator cap that can be used with CA-type materials, yet can be manufactured from different materials; for example a cap which can be manufactured (independently from the applicator) from materials which are not necessarily compatible with CA's. To that end, it would be desirable that coloured plastics be used in the construction of the applicator cap. Furthermore it would be desirable to simplify the process for filling a container with product and capping it subsequently with an applicator cap. It would also be desirable to provide applicators which are useful for particular purposes. In particular it is desirable to provide an applicator which will retain sufficient product on its free end for the application type in hand. It is desirable also to provide a mechanism for matching a cap profile to a profile of the container to which it is applied. Furthermore it is also desirable to provide a applicator cap which acts as a safety applicator cap.